Colvin, an American reporter for the British newspaper, and photographer Remi Ochlik both died in the attack.

Shells hit the house in which the two veteran war correspondents were staying, then they were killed by a rocket as they tried to make their escape.

John Witherow, Editor of The Sunday Times:

Marie was an extraordinary figure in the life of The Sunday Times, driven by a passion to cover wars in the belief that what she did mattered. She believed profoundly that reporting could curtail the excesses of brutal regimes and make the international community take notice. Above all, as we saw in her powerful report last weekend, her thoughts were with the victims of violence.

Throughout her long career she took risks to fulfil this goal, including being badly injured in Sri Lanka. Nothing seemed to deter her. But she was much more than a war reporter. She was a woman with a tremendous joie de vivre, full of humour and mischief and surrounded by a large circle of friends, all of whom feared the consequences of her bravery.

It is with great sadness that I have learned of the death of Marie Colvin, one of the most outstanding foreign correspondents of her generation, who was killed in Homs in Syria today while reporting for The Sunday Times.

She was a victim of a shell attack by the Syrian army on a building that had been turned into an impromptu press centre by the rebels. Our photographer, Paul Conroy, was with her and is believed to have been injured. We are doing all we can in the face of shelling and sniper fire to get him to safety and to recover Marie’s body.

Marie had fearlessly covered wars across the Middle East and south Asia for 25 years for The Sunday Times. She put her life in danger on many occasions because she was driven by a determination that the misdeeds of tyrants and the suffering of the victims did not go unreported. This was at great personal cost, including the loss of the sight in one eye while covering the civil war in Sri Lanka. This injury did not stop her from returning to even more dangerous assignments.

This is a desperately sad reminder of the risks that journalists take to inform the world of what is happening and the dreadful events in Syria and our thoughts should be with her family and with her friends.

Marie Colvin embodied the highest values of journalism throughout her long and distinguished career as a foreign correspondent for the Sunday Times. For years she shined a light on stories that others could not and placed herself in the most dangerous environments to do so, including suffering injuries while reporting in Sri Lanka. She was utterly dedicated to her work, admired by all of us who encountered her, and respected and revered by her peers. Her tragic death is a terrible reminder of the risks that journalists take to report the truth.

&lt;noframe&gt;Twitter: William Hague - Saddened by terrible news about Marie Colvin. She died helping people of Syria share their plight with the world. A great loss for us all&lt;/noframe&gt;

Jeremy Hunt, the Culture Secretary:

&lt;noframe&gt;Twitter: Jeremy Hunt - Tragic news about Marie Colvin, a brave woman and an excellent journalist. Thoughts are with her family and friends.&lt;/noframe&gt;

Nicolas Sarkozy, President of France:

This shows that enough is enough, this regime must go. There is no reason why Syrians should not have the right to live their lives, to freely choose their destiny.

She was one of the most fearless and dedicated reporters I have ever met in my 14 years covering war, and someone I looked up to as a hero and an inspiration.

For Marie, covering war wasn't about doing a few quick interviews and writing up a quick story: she experienced war alongside those who suffered in war, and her writings had a particular vividness because of what she had dared to see and experience. But despite everything she had seen and experienced, first and foremost she remained a wonderful human being, and it always put a smile on my face to run into her in one of the world's rough spots.

Bill Neely, ITV News international editor:

She took the deep breath over and over and plunged herself in, as deep as she could, to scoop out the nuggets we all need to know. And we were all, as a people, better for her. At a time when journalists are being examined as never before, it's time to acknowledge someone who made a difference, a moral difference, to our country and our lives.

The journalistic community have lost one of their finest and their most fearless. Marie Colvin was not only a brave and tireless reporter across many continents and in many difficult situations she was also an inspiration to women in her profession.

Ed Miliband

Helen Fielding, the author and a close friend of Ms Colvin's:

She said in a statement: "Marie Colvin was the bravest and best of women, the most fearless and committed of journalists, and the dearest, most loyal and wildest fun of friends. I am so sad and so proud of her. Marie's life's work was to expose the excesses and brutalities of war with accuracy, without prejudice and in the hope of curtailing those excesses. It's to be hoped that there will be action to end the Syrian brutality which has cost Marie's life and that of countless others.

Kate Allen, director of Amnesty International UK:

Marie Colvin was a truly brilliant journalist who fearlessly reported on terrible abuses of human rights around the world. We are shocked and saddened at her death, which is a terrible loss to journalism in this country.